To provide a run flat tire capable of traveling a comparatively long distance in a deflated condition evacuated in the tire due to puncture, etc.

A side reinforcing rubber layer 10 provided with a plurality of recessed groove-shaped recessed parts 21 extending to the tire radial direction inside/outside and separating in the tire peripheral direction is provided on an internal surface on a tire inner cavity side of a reinforcing base part 20 formed into a substantially crescent-shape in cross section in a side wall part 3 and on a tire inner cavity side of a carcass 6. An internal side reinforcing rubber layer 10i located at the vehicle inside and an external side reinforcing rubber layer 10o located at the vehicle outside have substantially the same shape in cross section. By differentiating at least one element of specifications to be a cross-sectional shape of the peripheral direction or the radial direction including a length L, a depth D and a width W of the recessed part 21, an angle θ in relation to a radial line or peripheral direction pitch P between width center lines of the recessed parts 21 between the internal and external side reinforcing rubber layers 10i and 10o, longitudinal rigidity of an external side wall part 3o is made larger than that of an internal side wall part 3i.

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